Grinding machine

ABSTRACT

This invention relates to a grinding machine and, more particularly, to apparatus for generating a surface of revolution by the abrasive process, substantial portions of the grinding cycle being controlled by digital means.

Unite States Patent Robillard et a1. 5] Jan. 18, 1972 [54] GRINDING MACHINE [561 References Cited [72] Inventors: Edward G. Robillard, Cherry Valley; UNITED STATES PATENTS ggrgi ga wg z ggi zfl ig Eg 3,269,064 8/1966 Lockwood ..5 1/1659 x 3,327,432 6/1967 Lockwood ..51/l65.87 [7 A sign l The Heald Machine Company, Worcester, 3,403,480 10/1968 Robillard ..51/l65.87 Mass. 3,503,158 3/1970 Robillard et a1. ..5 1/1658 [22] Filed: 1969 Primary Examiner-Lester M. Swingle [21] App]. No; 879,785 Att0rney-Norman S. Blodgett [57] ABSTRACT [52] U.S.Cl ..51/165.8 [51] lnt.Cl ..B24b 49/00 This invention relates to a g g machine and, more P [58] Field of Search ..51/165.77, 165.8, 165.87, 165.9 ticularly, r9 apparatus for generating a surface f l i n by the abrasive process, substantial portions of the grinding cycle being controlled by digital means.

9 Claims, 37 Drawing Figures PATENTEUJAHWBTZ 3 979 SHEET GlOF 36 FIG. 1

INVENTORS EDWARD G. ROBILLARD ROBERT H. LIZOTTE HERBERT R. UHTENWOLDT ATTORNEY PATENTEDJANK 8191 2 SHEET CZUF 36 PATENTEEJANIBEYZ $634379 SHEET 030F 36 FIG. 3

PATENTED JAN 1 81972 SHEET GHUF 36 PATENTEDJANHSIQYZ 5%34979 SHEET UBUF 36 PATENTEnJAmemz 3f341979 I saw near 30 IO 6 58 STEPPING MOTORH 63 2a STEPPING MOTOR 2 FIGS (2ND GAGE) INTERMEDIATE SIZE R o 0 E55 SIZE I ST. GAGE) RELIZACT FIRST 5|ZE RETRACT QQRDGAGE) (GAGE RELEASE) -*il FINAL DRESS u SIZE FINISH TABLE OUT PATEHTEU JAN! 8 I372 2.6341979 SHEET 12UF 36 I am 57A} CYCLE BACKING PLATE ,V OFF POWER SUPPLY 83 HAND AUTO 56 5| 5? v 6 LS-56 v 307 CHUCK COIL 5a ammo amp. 5?

conTmL cmcw'r GHD POWER SUPPLY +24 comm. M

+24 IZVOLT REG.

POWER SUPPLY --as +|2v 24v0c GAME 5? STEPPING MOTOR GHD POWER SUPPLY v +24v com.

130: v50! 4o| FIG I3 I 401 301v PATENTEU JAN 1 81972 SHEET 307 SLO SYN TYPE as 250 STEPPING MOTOR 01 K5 K6 K7 as 302 CROSS SLIDE OFF AUTO SETUP K..2 K4 -m- 1 I K-I? +346 1 E Y K-l9 K-ZO K- H347 A ll'z l l 45A K3 Hzv :sa5" 3M5? FRONT 46RR-l s-a 9-M 46A SLIDE REAR O O 256" 22 LIMIT H9 NEW WHEEL RESET STD COMP -K-24 45RR g1 FRNT J .STD. come 4 Lifiggww K25 REAR K28 COARSE come K26 FRONT +24v (IB) COARSE com? REAR COMPENSATION SLIDE CONTROL UNIT SKIP amass cou l5PR-l no NTER 5| fin "IEPR-l FIG. l5

OFF ON INTERLOCK OJZ' F. Q N

PATENTEB JAN 1 8 I972 NO PART SHEET lS IF 36 NO PART NO GRINDING FORCE FIRST SIZE FIRST SIZE FIRST SIZE SPARKOUT TIMER FINAL FORCE 2ND SIZE SPARKOUT TIM ER DRESS DRESS SIZE FINAL SIZE 

1. A grinding machine for finishing a surface of rotation of a workpiece, comprising a. a base, b. a workhead table mounted on the base and adapted to support the workpiece, c. a wheelhead table mounted on the base and adapted to support a rotatable spindle with the abrasive wheel, d. means for supporting one of the tables for sliding motion transversely of the axis of the surface of revolution, e. a secondary slide associated with the said one of the tables and mounted for sliding transverse motion independently of the said one of the tables, f. a first stepping motor connecting the base to the secondary slide for bringing about its sliding motion, and g. a second stepping motor connected on occasion between the said one of the tables and the secondary slide to produce the sliding motion of the table.
 2. A grinding machine as recited in claim 1, wherein the surface of revolution which is to be finished is an internal surface, wherein the spindle is mounted as a cantilever with the abrasive wheel mounted at the free end, and wherein a dressing apparatus is mounted so as to be free of the movement of the said one of the tables and of the secondary slide.
 3. A grinding machine as recited in claim 2, wherein the said one of the tables is the wheelhead table, wherein the workhead table is mounted for longitudinal movement relative to the wheelhead table, and wherein the secondary slide is a compensation slide.
 4. A grinding machine as recited in claim 3, wherein a control is provided to actuate the stepping motors so that the first stepping motor is used for dress compensation movements and the second stepping motor is used for feed rate grinding movements and retraction movements.
 5. A grinding machine as recited in claim 4, wherein the control presents electrical pulses to the stepping motors, and wherein the pulse frequency and the total number of pulses presented during a given movement are adjustable.
 6. A grinding machine as recited in claim 5, wherein a hydraulic cylinder connects the wheelhead table to the base to produce a controlled force grinding movement, wherein a retractable stop extends from the wheelhead table for engagement with the compensation slide on occasion to restrict the said grinding movement, and wherein the second stepping motor is connected to retract the stop relative to the wheelhead table at a controlled rate.
 7. A grinding machine as recited in claim 6, wherein the control contains means for introducing a first predetermined number of pulses to the second stepping motor at one point in the grinding cycle for a retraction movement and introducing a second different predetermined number of pulses to the second stepping motor at another point in the grinding cycle for another retraction movement.
 8. A grinding machine as recited in claim 4, wherein means is provided to bring about longitudinal reciprocatory movement between the workhead table and the wheelhead table during the grinding cycle, and wherein the control contains means to introduce the pulses to the second stepping motor at the ends only of the reciprocatory motion for feed rate grinding movement at that time.
 9. A grinding machine as recited in claim 4, wherein the control contains means for introducing to the second stepping motor feedback pulses to compensate for long-range variations in the quality of the finished surfaces of successive workpieces. 